Firefish unhappy

[Jerry Gunn]

I bought a Firefish (Fish 1) for a new marine aquarium. I fed it enriched artemia. It did well and ate vigorously. I thought I would get it a companion for it so I bought another same color FIrefish (Fish 2). I picked the largest one I could find hoping to get a happy pair. I put it in the tank and they got along very well. They did everything together, even sleeping. Fish 2 was dominant and swam and ate just above the original Fish 1. They lived well together for about 3 weeks.

Then I noticed Fish 2 was breathing about 4 times normal rate. And Fish 1 was now acting domninant and breathing/eating very normally. Fish 2 shows no sign of disease and looks good, but is losing weight and hiding a lot more. This has been going on for about 3 weeks. Now, Fish 2 breathing has slowed a bit (still too fast), but is still losing a little weight. It still shows no sign of disease and its fins look great and are flared nicely. I'm pretty sure it won't survive if it does not start eating more. I have not seen any aggression and they still sleep and spend time together. Fish 1 is still doing very well and breathing normally.

Any ideas what is going on with Fish 2 ? Old fish? Changing sex?

Bare bottom 10 gal tank, not a reef tank
Water parameters - 35ppt, pH = 8.2, NH3 = 0, Nitrate/Nitrite = 0
10% daily water change (Instant Ocean)
Small current in tank
Bubbler and Filter (Matrix + Carib Sea substrate in Filter bed)
Very Clean tank
Just a few decorations.
PVC pipe hiding place where they sleep and dart to.

 

[Old Fritz]

you shouldn't put two firefish together. even if you don't see it they will probably fight, or one will be submissive and will hide more and not eat. You will probably need to remove one of them

 

[vetteguy53081]

you shouldn't put two firefish together. even if you don't see it they will probably fight, or one will be submissive and will hide more and not eat. You will probably need to remove one of them

I have two in my 93 cube and they stick together like glue.
Three in my 660g and they stay together always

 

[Old Fritz]

I have two in my 93 cube and they stick together like glue.
Three in my 660g and they stay together always

"This member of the Gobiidae family is generally not aggressive towards other fish except those of its own species. However, a mated pair can live peacefully together. " - Live aquaria

Also keep them in my store. Occasionally jump tanks and one will beat the crap out of the other one

 

[Jerry Gunn]

you shouldn't put two firefish together. even if you don't see it they will probably fight, or one will be submissive and will hide more and not eat. You will probably need to remove one of them

That 's a good idea. I will build a mesh tank divider tonight and see how that works out. Thanks for your help.